Like “entity”, the word “attribute” has a specific technical sense when used in the SGML context, which differs somewhat from its sense when used in the database design context. An SGML attribute is a category of information associated with a particular type of element, but not contained within it. Attributes are associated with particular element occurrences by including their name and value within the start-tag for the element concerned. For example:
Call me <name type="Biblical">Ishmael</name>.
Here “type” is the name of an attribute associated with any occurrence of the <name> element, “Biblical” is the value defined for this attribute in the case of the example <name> above.
Attributes are used for two related purposes: they enable an identifying number or name to be associated with a particular element occurrence within a text (which might otherwise be missing), and they enable additional information missing from a text to be added to it without violating its integrity.
Een attribute bij een element kan verdere informatie aan dat element geven en wordt in een ATTLIST in de DTD verklaard.
The purpose of an attribute specification is to add some extra information about an element occurrence beyond its name.